Wheel-rail wear progression of high speed train with type S1002CN wheel treads

A calculation method for contact bandwidth and its change rate is developed. The method can be used to quantify the wheel-rail contact point geometry relationship and evaluate the quality of type S1002CN wheel tread after undergoing a tread reprofiling process, as well as to analyze a trend of the wheel-rail contact state and the tread wear state. Firstly, the wheel tread shapes of type S1002CN are measured with increasing train operation distance covered in one wheel tread reprofiling cycle. Secondly, wheel-rail indexes, such as cumulative wear, equivalent conicity, contact bandwidth and its change rate, are calculated in order to obtain the change trend. Finally, a diagram of contact points on the wheel surface can be drawn over the whole tread reprofiling cycle. Based on the calculation results, the contact bandwidth and its change rate are more sensitive than the equivalent conicity, and a more comprehensive assessment for the worn shape of the wheel tread, the running stability of the vehicle, the wheel-rail contact state and the tread wear state has been established. The method has been applied to research on the wear of wheel treads of high speed train, and the results show that the calculation and evaluation methods are reasonable and viable.